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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 6 |
| 3 | 29 |
| 4 | 221 |
| 5 | 1897 |
| 6 | 23502 |
| 7 | 335334 |
| 8 | 5923570 |
| 9 | 119354491 |
| 10 | 2758647259 |
| 11 | 71079498533 |
| 12 | 2031108928680 |
| 13 | 63520842121792 |
| 14 | 2161164726505952 |
| 15 | 79394066773371245 |
| 16 | 3133259427956392983 |
| 17 | 132166451829847198316 |
| 18 | 5934636812034634649249 |
| 19 | 282609413111134846839482 |
[1,1,6,29,221,1897,23502,335334,5923570,119354491, 2758647259,71079498533,2031108928680, 63520842121792,2161164726505952,79394066773371245, 3133259427956392983,132166451829847198316, 5934636812034634649249,282609413111134846839482] |